成渝线典型路基边坡对降雨过程的响应模拟

A Simulation of the Hydraulic and Mechanical Response to the Rainfall Process of the Typical Subgrade Slope in Chengdu Chongqing Railway

成渝铁路典型路基边坡由砂泥岩互层及其风化带组成,顶部为2～5m的砂粘土层。模拟实验表明,边坡对降雨过程的水力学及力学响应取决于土层的初始渗透性、降雨方式和降雨量;能够对边坡渗流场和应力场产生明显影响的降雨过程一般应同时满足3个条件:(1)雨前经历过较长时间的炎热天气,土层蒸发强烈、初始渗透性良好;(2)降水过程以中到大雨开始,且持续较长时间;(3)降雨时间长。

The typical subgrade slope of Chengdu Chongqing railway is made of sandstone mudstone layers and its weathering zones are covered by a sand layer with a thickness of 2～5 m. Simulation tests indicate that the hydraulic and mechanical responses of the slope to a rainfall process is influenced by the initial permeability of the sand layer, the rainfall style and the rainfall amount. The rainfall process which can have a remarkable influence on the seepage field and stress field of the slope should satisfy the following requirements simultaneously: (1) due to a long time of hot weather before rain, the soil layer is intensely evaporated and its initial permeability is good; (2) the rainfall process begins with a moderate or a heavy rain, and continues for a long time; and (3) the rainfall lasts a long time, and the rainfall amount is great.